Anhydrous protectant chemical composition

ABSTRACT

A highly resilient clear surface protectant is provided comprising of a copolymer, such as an isobutyl methacrylate, methyl methacrylate, or acrylic copolymer, in a hexamethyldisiloxane system. The hexamethyldisiloxane combined with a cosolvent package in a composition with a copolymer resin, such as an acrylic copolymer, enhances physical properties of coatings, such as unusual migration and spread and wetting on surfaces. The protectant formulation exhibits greater substantivity to surfaces such as aluminum, steel, brass, stainless steel and copper, and possesses enhanced spreading ability on surfaces to which it is applied resulting in improvement in physical properties in protection of metal surfaces against the deterioration caused by oxidation, degradation and corrosion.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention is directed to a surface protectant composition for useon metal surfaces. More specifically, embodiments of the invention aredirected to an anhydrous protectant composition including one or morecopolymers, a cosolvent and hexamethyldisiloxane (HMDS).

2. Description of Related Art

Surfaces such as marine metal surfaces are becoming widespread.Increased use of various marine metal surfaces has caused demand forprotecting; rust proofing, corrosion resistance, preserving, as well asprotecting various metal surfaces exposed to highly corrosiveenvironments. Metal protectants generally provide a high level of glossto metallic surfaces, restore the appearance of the metal surface, andprotect the surface against the environmental influences, heat, oceanwater salt, ocean water immersion, salt fog, marine environment, acidrain, high humidity, and ultraviolet rays. In addition to providing awater repellent film on the surface, protectants typically offersprotection against the effects ultraviolet radiation, and otherenvironmental causes of degradation.

It is known that various polymer systems can be employed as aningredient in formulations for application to surfaces, such as metalslike aluminum, copper, brass, and stainless steel for the purpose ofproviding a protective coating. However, when products known in the artare applied as protective coatings for outdoor surfaces, such as marineapplication railings, metal surfaces including aluminum, copper andbrass, or automotive metal surfaces, the coatings do not coat, spreadand wet the surfaces at the rapid rate of this invention, resulting incoatings with surface, appearance and performance that is not desirable.Furthermore, some of the commercial coatings can rapidly abrade,corrode, discolor under heat and do not have good gloss or resilience.

SUMMARY

An object of the invention is to create a migrating protective coatingwith rapid spread resulting in enhanced cure rate, tensile modulus anddurability in an exempt hexamethyldisiloxane system that results in aprotective coating with enhanced shear modulus, degree of crystallinityand hardness for the substrate being protected.

A further object of the invention is to provide a copolymer system in ahexamethyldisiloxane solution system containing a copolymer such asacrylic, methacrylic, and isobutyl acryilic copolymers, that provide ametal surface with unusual physical and chemical resistance and luster.

It is a further object of the invention to include in the protectivecoating a cosolvent compatibilizer system comprising one or more ofsolvents selected from isopropyl alcohol, acetone, and dipropyleneglycolmonopropylether (PNP) that make a protectant composition solution ofacrylic methacrylic and/or isobutyl acrylic solution in hexamethyldisiloxane possible, combined with a high degree of spreadability.

It is a further object of the present invention to provide a protectantformulation which exhibits greater substantivity to metal surfaces suchas aluminum, brass, copper, steel, stainless steel, and other metalsurfaces used in marine and automotive applications.

It is a further object of the invention to enhance the migration andspread of the a protectant on surfaces, in particular metallic surfaces,and to impart high spread rate, resulting in an improvement of gloss,luster and protection of such surfaces against the deterioration causedby rust, corrosion, heat and environmental conditions.

It is a further object of the invention to provide a protectantcomposition with the ability to migrate, spread and wet surfaces at arate of spread of about 5 centimeters diameter per 1-2 drops of liquid,which cures within about 3-5 minutes, rendering protection against harshenvironmental conditions.

DETAILED DESCRIPTION

Embodiments of the present invention are directed to a composition foruse in protecting metal surfaces, such as surfaces of land and marinevehicles. In particular embodiments, the composition is an anhydrouscomposition that comprises hexamethyldisiloxane (HMDS), a copolymersolvent, and a cosolvent.

In accordance with the present invention, a high spread metal protectantcoating is developed which offers the advantage of extreme protection ofsurface against marine salt water, heat, corrosion, degradation. Uponapplication, the protectant composition shows extremely rapid migrationand spread, where 1-2 drops of the material can migrate and spread to adiameter of about 5 cm diameter, leaving a highly lustrous protectivesurface on metallic surfaces. It has also been found that theprotectants of the present invention provide better protection againstheat, marine salt water and radiation in comparison with leadingcommercial protectant formulations. Such advantages are believed to flowfrom the presence of high spread copolymer resin in hexamethyldisiloxane HMDS in compatiblizer solvent package making it possible forthe coating to migrate and spread a diameter of about 5 cms per 1-2drops, and achieving about 1-4 micron thickness that results in optimalcure, about 3-5 minutes tack free time and cure and crosslink whichenhances crystalinity and shear modulus and unusual physical durability.

In this invention the combination of silicone polymerhexamethyldisiloxane with copolymer system and compatiblizer cosolventsystems render a solution capable of migrating, and extremely rapidspread rate that results in ultra thin about 1-4 micron protectant andenhanced cure, crosslink density and tensile modulus combined withprotection of surface in the fashion contemplated in accordance with thepresent invention is believed to be new. Physical properties includerapid migration, spread and wetting, fast dry, high humidity resistance,UV exposure, over 4 months roof exposure, immersion resistance, nofading or yellowing, and marine environment exposure for aluminum andstainless steel as well as salt spray, and exposure to acids and bases.

The protectant composition of the present invention includeshexamethyldisiloxane (HMDS), a copolymer solvent, and a cosolvent. Thecopolymer may be one or more of the following: acrylate copolymers,isobutyl methacrylates, methyl acrylates, methyl metacrylates, andacrylic polymers. The cosolvent may include one or more of thefollowing: isopropyl alcohol, dipropylene glycol monopropyl ether (PNP),exempt solvent acetone, and dimethylketone.

The solvent solution is obtained by dissolving a copolymer solution intoa the cosolvent system (which is a compatibilizer). The resultantsolution is then added to exempt hexamethyldisiloxane over about 1-3minutes.

In particular embodiments, the compositions of the present inventionhave a specific gravity of about 0.81 to about 0.83 g/ml. In furtherembodiments, the compositions show about 3 to about 5 minutes of drytime when aerosolized and spray applied. The compositions have highgloss, are highly resilient to humidity, and are highly resistant totemperature. The thickness of application achieved by the compositionsin particular embodiments is between about 1 to about 4 microns.

In preferred embodiments, the protectant composition shows the followingproperties: an average thickness on a metal surface of about 1-4microns, a spread/wetting of about 4-5 cm by 1-2 drops of composition, adry to touch time of about 3-5 minutes, and a high gloss that isbrilliant and glossy. In particular embodiments, the composition canwithstand a high humidity over 3 months of 52° C., 45° C., or roomtemperature and an ocean water immersion over 3 months of 52° C., 45°C., or room temperature. A metal surface coated with the protectantcomposition shows no effect of exterior exposure in a marine environmentover 4 months, no effect of roof exposure in a marine environment over 4months, and no yellowing or discoloration of UV exposure over 3 months.In embodiments the protectant composition shows heat resistancy to 842°F. (450° C.), does not fade or haze, withstands acids for over 30minutes, resists 3% salt water for over 3 months, resists 3% salt waterin high humidity for over 3 months, resists salt fog for 86 hours withno yellowing/discoloration, and can be cured in ambient temperaturewithout heat or baking.

The solution of copolymers in cosolvent compatibilizer and HDMS areclear liquids. In preferred embodiments, the liquids are nonirritatingto the skin and exhibit unusual migration and spreadability when appliedto metal surfaces. Once applied, the materials evaporate, leaving a thinlayer of copolymer cured resin that dries to a high gloss, unusuallyresistant protectant coating.

A method of providing the protective coating to a metal substrate, suchas marine metal surfaces, which are exposed to highly corrosiveenvironments, involves aerosol spray application to the metal substrateof the protectant composition.

The protectant composition includes copolymer solution, preferably amethyl methacrylate, isobutyl acrylate, methyl methacrylate, ethylacrylate, propyl acrylate, methylpropyl acrylate, butylacrylate,isopropylacruylate, and/or methyl isopropyl acrylate. The copolymersolution is preferably about 25 to about 33 percent by weight of theprotectant composition. The copolymer solution may be predissolved in acosolvent system. The cosolvent system may contain isopropyl alcohol(about 5 to about 9 percent by weight in the overall protectantcomposition), dimethyl ketone (about 5 to about 9 percent by weight inthe overall protectant composition), and dipropylene glycol monopropylether (PnP) (about 18 to about 25 percent by weight in the overallprotectant solution).

The premixed solution of the copolymer solution in the cosolvent systemmay then be introduced gradually into hexamethyl disiloxane (HMDS),which may be at about 30 to about 38 percent by weight of the finalcomposition. The premixed solution and HMDS may be allowed to mix forabout 3 to about 5 minutes. The resulting solution is preferably clearand has a specific gravity of about 0.63 to about 0.68 g/ml.

In further embodiments, other silixone fluids than HMDS may be used, forexample, ciclomethicones, dimethicones, hexamethylsiloxanes, exemptvolatile siloxanes (e.g., at about 0.65 centistokes), polydimethylsiloxanes (e.g., at about 1 centistoke), octamethyltrsiloxanes,decamethyltetrasiloxanes, dodecamethyltetrasiloxanes,polydimethylsiloxanes (e.g., at about 3 centistokes),dodecamethylpentasiloxane, and dimethicones (e.g., at about 5, 10, or 20centistokes). Other volatile silicone fluids include dimethicone (e.g.,at about 1 centistoke), dimethicone (e.g., at about 1.5 centistokes),dimethicone (e.g., at about 2 centistokes), cyclotetrasiloxane,cyclopentasiloxane, cyclohexasiloxane, and cyclomethicone (e.g., atabout 3.5 centistokes).

The physical properties provided by the finish of the present inventioncan be attributed to the presence of the combination of copolymer resinscompatibilized by the cosolvent system into the hexamethyl disiloxanesystem. This combination provides a protectant that has greaterspreadability and enhanced protection in comparison to commercialformulations that do not contain the combination of copolymer resinswith hexamethyl disiloxane solvent. Hence, the compositions of thepresent invention possess a more pronounced spreadability and physicalresilience on metal surfaces. This is of particular significance inmarine outdoor applications where the treated surface is exposed tovaried and harsh weathering conditions.

In this invention it is contemplated that the composition of copolymerdissolved in HMDS with compatibilizer cosolvents has superior spreadproperties allowing the uniform migration of copolymer and maximizes theeffect of crystalinity, minimizing rubbery amorphous properties andenhancing coating modulus, and producing highly resilient andtemperature resistant clear coating protectant.

Unusually rapid spread of coating allows coating of about 1-4 micronsthick protectant film that maximizes optimum crosslinking and full curein lowest possible thickness, as a result of increasing modulus inrubbery regions with increased cure rate and crosslinks as molecularweight between crosslinks decrease, resulting in high shear modulus,increased Tg, which in turn enhances shear modulus and giving hightemperature resistance of up to 450° C. (842° F.), higher than all othercompetitive products.

The compositions described herein are particularly useful on metalsurfaces such as aluminum, copper, brass, steel, and stainless steel.

EXAMPLE I

A solution was made of the components in Table I.

TABLE I % weight HMDS 35.5 PNP 21.0 Acetone 7.5 Luster Seal-300 (LS-300)Copolymer 28.5 (a methyl methacrylate copolymer from Tamms Industries,Inc.) Isopropyl Alcohol 7.5

A commercially available copolymer paraloid B-67 45% from Rohm and Haas,or surface sealer comprising an acrylic copolymer can be used at a ratioof 28.5%, is dissolved in a cosolvent blend comprising 7.5% isopropylalcohol (IPA), 7.5% acetone and 21.0% dipropyleneglycol monopropyl ether(PNP).

The mixture was mixed at an ambient temperature for about 1-3 minutes toform a clear solution. The solution was then added to 35.5% by weight ofhexamethyl disiloxane (HMDS) that can be commercially obtained asVolasil DM 0.65 or Volasil DM 0.65 SP from Chemsil Inc.

The resulting solution was clear and had physical properties including:specific gravity=0.83 g/ml; dry to touch time=5-7 min; averagethickness=1-4 microns.

1-2 drops of the resulting solution when dropped over a metal surfacehad spread capabilities of about 4-5 cm in diameter, which is an unusualresult of a combination of a copolymer system with HMDS and a cosolventsystem. The resulting solution was packaged in a spray applicator andspray applied to several test substrates of aluminum, brass, copper, andstainless steel surfaces. The coated surfaces were tested in extendedexposures in marine environments for protection. Evaluations of thetreated surfaces revealed the unique spread, migration and wettingcharacteristics of the invention resulting in an extremely resilientprotective coating. The results following outdoor exposure revealed thatthe surfaces treated with the composition produced a continuous highergloss shinier appearance than other competitive products not utilizingHDMS/copolymer/cosolvent mixture, and would spread and wet surfacesbetter than the surfaces treated with the competitive products. Surfacestreated with the composition of this example and the other examplesrevealed in exterior testing of withstanding 4 months in a marineenvironment, as well as unique physical properties of heat resistance(about 450° C.), water repellency, and immersion tests in ocean saltwater.

EXAMPLE II

A solution was made of the components in Table II.

TABLE II % weight HMDS 39.8 PNP 21.0 Acetone 7.5 Paraloid B-67 45% 24.2Isopropyl Alcohol 7.5

The steps of Example I were repeated. Evaluations were the same asindicated in Example I.

EXAMPLE III

A solution was made of the components in Table III.

TABLE III % weight HMDS 39.75 PNP 21.0 Acetone 7.5 Paraloid B-67 45%28.5 Isopropyl Alcohol 7.5 F-810 0.05

The steps of Example I were repeated, except that F-810 fluorinatedcopolymer, a fluorinated silanol fluoropolymer from API, Inc., was addedat 0.5%. Evaluations were the same as indicated in Example I. It wasnoted that the solution had exceptional wetting and spread ability onmetal surfaces such as aluminum and marine stainless steel, copper andbrass surfaces.

EXAMPLES IV-VII

Additional solutions were made of the components in Tables IV-VII,prepared in the same manner as Example I and exhibited similarproperties.

TABLE IV % weight HMDS 42.8 PNP 24.0 DMK 16.0 Paraloid B-67 45% 17.2

TABLE V % weight Chemsil 0.65 84.7 D-536 5.0 (amino functionalizedreactive silicone fluid from Dow Corning Co.) Dow 20 10.0(polydimethylsiloxane moisture cure coating from Dow Corning Co.) A-11100.3 (gama-aminopropyltrimethoxysilane from GE Silicones)

TABLE VI % weight HMDS 35.5 PNP 21.0 Acetone 7.5 B-67 MT 28.5(methacrylic resin PARALOID B-67 MT from Rohm & Haas) Isopropyl Alcohol7.5

TABLE VII % weight HMDS 16.5 PNP 8.5 Paraloid B67 45% 74.8 Butter scotchfragrance 0.2

The steps of Example I were repeated, except that F-810 fluorinatedcopolymer was added at 0.5%. Evaluations were the same as indicated inExample I.

While the description above refers to particular embodiments of thepresent invention, it will be understood that many modifications may bemade without departing from the spirit thereof. The accompanying claimsare intended to cover such modifications as would fall within the truescope and spirit of the present invention.

The presently disclosed embodiments are therefore to be considered inall respects as illustrative and not restrictive, the scope of theinvention being indicated by the appended claims, rather than theforegoing description, and all changes which come within the meaning andrange of equivalency of the claims are therefore intended to be embracedtherein.

1. A surface protectant composition comprising about 30% to about 38% byweight of hexamethyldisiloxane, a resin solution comprising a copolymerof methyl methacrylate and a monomer selected from the group consistingof alkyl acrylates having 4 to 7 carbon atoms, isobutyl methacrylate,and n-butyl methacrylate, and a cosolvent of at least two solventsselected from a group consisting of acetone, isopropyl alcohol anddipropylene glycol monopropyl ether, wherein the surface protectantcomposition has high surface spread on metal surfaces.
 2. The surfaceprotectant composition of claim 1, wherein the copolymer is a copolymerof methyl methacrylate and isobutyl methacrylate or n-butylmethacrylate.
 3. The surface protectant composition of claim 1, whereinthe surface protectant composition exhibits a spread about 5 centimetersdiameter per 1-2 drops of liquid.
 4. The surface protectant compositionof claim 1, wherein the surface protectant composition exhibits a curetime of about 3 to about 5 minutes.
 5. The surface protectantcomposition of claim 1, wherein the surface protectant compositionachieves 1-4 micron thickness when used as a surface protectant.
 6. Thesurface protectant composition of claim 1, wherein a metal surfacecoated with the surface protectant composition shows no effect ofexterior exposure in a marine environment over 4 months.
 7. The surfaceprotectant composition of claim 1, wherein a metal surface coated withthe surface protectant composition shows no effect of roof exposure in amarine environment over 4 months.
 8. The surface protectant compositionof claim 1, wherein the surface protectant composition shows heatresistance to 450° C (842° F).
 9. The surface protectant composition ofclaim 1, wherein the surface protectant composition can be cured inambient temperature without heat or baking.
 10. The surface protectantcomposition of claim 1, wherein the surface composition resists 3% saltwater.
 11. The surface protectant composition of claim 1, wherein thesurface protectant composition resists salt fog with noyellowing/discoloration.
 12. A surface protectant composition of claim1, wherein the surface protectant composition comprises about 30% toabout 38% by weight of hexamethyldisiloxane, a solvent including acopolymer of methyl methacrylate and a monomer selected from the groupconsisting of alkyl acrylates having from 4 to 7 carbon atoms, isobutylmethacrylate, and n-butyl methacrylate, and a cosolvent of at least twosolvents selected from a group consisting of acetone, isopropyl alcoholand dipropylene glycol monopropyl ether.
 13. A surface protectantcomposition comprising about 30% to about 38% by weight ofhexamethyldisiloxane, a resin solution comprising a copolymer of methylmethacrylate and a monomer selected from the group consisting of alkylacrylates having from 4 to 7 carbon atoms, isobutyl methacrylate, andn-butyl methacrylate, and at least two solvents selected from a groupconsisting of acetone. isopropyl alcohol and dipropylene glycolmonopropyl ether.
 14. The surface protectant composition of claim 13,wherein the copolymer is selected from the group consisting of acopolymer of methyl methacrylate and an alkyl acrylate having from 4 to7 carbon atoms, a copolymer of methyl methacrylate and isobutylmethacrylate, and a copolyrner of 45 mole % methyl methacrylate and 55mole % n-butyl methacrylate.